Keep in mind the military method would be to kill all the enemy, unless they wanted to keep someone alive for intel or the like.

There are many military teams that train for the hostage rescue mission that you mention, but you also say that everyone in the room is considered armed and dangerous, so where are the hostages? If there are no hostages in the room, you really wouldn't need to go in would you?

Most military teams have the luxury of larger entry teams, though a smaller room will dictate fewer operators. I will refrain for addressing military tactics any further since that is not my background.